Stadia-transit.



W. L. E. KEUFFEL.

STADIA TRANSIT.

APPLICATION FLLED DEC. 10. 1913.

Patented Sept.v 21, 1915.

2 SHEETSSHEET 1.

Attest: flaw/7f 4 Zflfb Inventor:

by M r 4? Artfv.

W. L. E. KEUFFEL.

STADIA TRANSIT.

APPLICATION FILED DEC. 10. I913.

Patented Sept. 21, .1915.

2 SHEETS-SHEET 2.

COLUMBIA PLANOGIIAPH co.. WASHINGTON, n. c.

UNITE TATE i WILLIE L. E. KEUFFEL, I-IOBOKEN, NEW JERSEY, ASSIGNOR TO THE KEUFFEL & ESSER COMPANY, OF HOBOKEN, NEW JERSEY, A COR-FORA'IIGN OF NEW JERSEY.

ATENT @FFEQFQ.

STADIA-TRANSIT.

Specification of Letters Patent.

Patented st rt. at, 1915.

Application filed December 10, 1913. Serial No. 805,821.

To all whom it may concern.

Be it known that I, lVILLIn L. E. Kenn run, a citizen of the United States, residing at Hoboken, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Stadia- Transit, of which the following is a specifi cation.

This invention relates to a device adapted to beattached to a surveyors transit for the purpose of taking stadia readings directly in terms of horizontal and vertical distance without the use of formulze, charts, elaborate tables or slide rules, and its novelty consists in the construction and adaptation of the parts, as will be more fully hereinafter pointed out.

Surveyors transits, as part of their usual equipment, usually comprise a telcscope'provided with three fine horizontal cross wires called stadia wires and with a vertically arranged are or circle secured to the telescope and the center of which is coincident with the center of oscillation of the telescoge. In use, a rod man sets up his stadia rod at a point the distance of which from the place where the telescope is erected is to be determined. Assuming that the rod and telescope support are both resting on a level surface, the observer looks through the tele scope and reads on the rod the distance which the upper and lower stadia wires of the telescope apparently subtend. This distance, multiplied by a constant factor (usually 100 or thereabout), gives the distance between the instrument and the rod. If the instrument is not on a level with the rod it must be inclined in order to sight the rod. lVhen the rod has been sighted and the distance on it apparentlv subtended by the upper and lower stadia wires has been read, this reading multiplied by the constant referred to no longer gives the correct distance because of the angle of inclination of the telescope. In order to ascertain the correct horizontal distance the formula rc r cos. a

must be used in which 00 is the required distance, 1 is the observed stadia distance and a is the angle of the inclination of the telescope to the horizontal. In order to ascertain the difference in elevation, or level, between the rod and the instrument the for mula 1 :{r sin. a

must be employed in which 3 is the required distance and the other factors are as before. It is obvious that the ascertainment of distances by the use of such formula involving sines and cosines and arbitrary factors involves much labor in computation and, on account of the tables which are employed, results in errors of observation and calculation which should be avoided if possible.

As stated above, the telescope of such an instrument is provided with a vertical. circle or are swinging with it and by which its angular displacement is -measured. Practically only the upper and lower quadrants of this circle are graduated because when the telescope is tilted beyond such graduations the line of sight is obstructed by the frame of the instrument or the rod is outside of a practical position. I employ the right and left quadrants of this circle which are practically of no value and are left blankfor the purpose of placing thereon accurately calculated scales whereby there may be read directly on such scales factors for both the horizontal and vertical distance of the rod which multiplied by the observed stadia distance will give the correct distance without further computation.

In the drawings, in which there is illustrated an instrument embodying a preferred form of my invention, Figure 1 is a side elevation of the instrument; Fig. 2 is a detail of the index support and scale guard; Fig. 3 is a section through the same on the plane of the line 33 in Fig. 2, and Fig. i is a detail of the vertical circle showing the horizontal and vertical scales. Fig. 5 is a detail sectional view illustrating the mounting of one of the index segments.

In the drawings, 10 indicates the base of the instrument, 11 standards secured thereto in any usual suitable manner and terminating at their upper ends in aXle boxes 12, adapted to receive the trunnions 13 of the telescope 14. This latter is of any usual, or suitable, size and shape preferably one of the standard forms. Within the telescope tube and properly arranged intermediate the eye piece and objective there are provided the usual horizontal stadia wires. These are not illustrated because they are well known in the art. Between the legs of one standard on one side is adjustably secured, for in-- stance by screws 15, an arcuate Vernier 16 with it 0 point at the vertical center and immediately beneath. the center of oscillation of the telescope. Rigidly secured to one of the standards, in any suitably manner for instance by screws indicated at 18, is a guard and index holder 20 consisting of a central annular boss 21, radial ribs 22 and an outer ring 23, provided at two diametrically opposite places with recesses indicated at 24 and 25 and at a third intermediate place with a recess indicated at 26. This guard is preferably made of one piece of suitable metal. Adjustably secured in the recesses 2 1 and 25 by means of screws 27 that pass through the slots therein, or in any other suitable manner, are index segments one 28 marked Her. or I-Iorizontal, and the other 29 marked Vert. or Vertical or by any other suitable designation. The segments are adjustably mounted in order that they may be readily alined and that accuracy may thereby be obtained. It will be understood that this guard is mounted so that the inner peripheries of such segments are upon a circle the center of which coincides with the center of oscillation of the telescope and the arcs of which coincide with the outer periphery of a vertical circle 30. The outer periphery of the guard except where it is recessed is providedwith an internal annular flange 200.

Suitably secured to oscillate with the telescope tube is the graduated vertical circle 30 similar in construction with the standard equipment of this kind and having a central hub 31, radial spokes 32 and outer rim 33 which is graduated in its upper and lower quadrants (speaking of these in the position of the circle when the line of collimation of the telescope is horizontal) in degrees and minutes, about 60 each way right and left 7 the telescope but varying of course with the different angles.

7 Between the legs of the standard on which the guard 20 is mounted is the usual segment 16 carrying an index pointer and Vernier, as stated. v

The manner of the use of the device is scope and as the result is vertical scale will be at O opposite its in- Then the observed stadia subdex arrow. tention multiplied by 100 will equal the dis tance horizontally of the rod from the telescope and the same distance multiplied by 0 will equal the vertical height of the rod above or. below the tele- O it .is seen that the telescope and rod are on the same level. If the telescope must be tilted to see the graduations on the red, the observed readings multiplied by the indicated con- 7 stant factors on the scales opposite the fixed index pointers gives the vertical and horizontal distances at once. A small multiplication table will even permit of this computation being dispensed with.

The advantages of the invention seem obvious. Utilizing the usual vertical circle with which these instruments must be equipped as the carrier for the scales desired saves the manufacture of different scales and the cost of their attachment to the instrument. The horizontal and vertical scales being on the edge of the full circle the opportunity for a relatively coarse marking is afforded and great accuracy insured both in making and using the scales. The index pointers belng fixed after their initial adjustment at the shop by means of the screws they are not readily displaced, and as the pointers are on a plane surface coincident with the graduated surface of the circle accuracy of observation is promoted.

Not only that but as the horizontal and vertical scales are distinct and independent and each hasits own index, an error in observing one reading if made is not likely to be transmitted to the other. The guard which carried the index segments serves by its internal flange to save the circle from injury.

It is obvious that the positions of the horizontal and vertical scales may be interchanged or varied without departing from the principles of the invention.

What I claim is:

1. In an instrument of the character set forth, the combination with a support and telescope provided with stadia wires and mounted to oscillate on said support, of associated elements, one being on the support and the other moving with the telescope, said elements having scales "and coacting indexes, said scales being disposed at different points around the axis of movement of the telescope, one of said scales being graduated in terms of horizontal constants varying with each angle of inclination of the telescope, a second of said scales being graduated in terms of vertical constants varying with each angle of inclination of the telescope, and a third of said scales being graduated in terms of angular displacement.

2. In an instrument of the character set lorth, the combination with a support and a telescope provided with stadia wires and mounted to oscillate on said support, of a vertical circle fixed to the telescope and having its center coincident with the center of oscillation of said telescope, a guard ring extending over the circle and having cut out portions exposing the two vertical arcs of said circle and a horizontal arc of the same, one of said vertical arcs having a scale thereon graduated in terms of horizontal constants varying with each angle of inclination of the telescope, an element carrying an index for said scale carried by the guard ring, the other vertical arc of the circle having a scale thereon graduated in terms of vertical constants varying with each angle of inclination of the telescope, a second element having an index for said second scale carried by the guard ring, the horizontal ex posed arc of the circle having a third scale mounted to oscillate on said support, of

vertical circle having its center coincident with the axis of 0s 'illation 01 the telescope and fixed to said telescope, said circle having a scale on one are graduated in terms of horizontal constants varying with each angle of inclination of the telescope, and having a second scale on another are graduated in terms of vertical constants varying with each angle of inclination of the telescope, separate elements carrying indexes for the said scales, securing means for the elements permittin g their adjustment and normally holding them against movement, a third are of the circle having a third scale graduated in terms of angular displacement, and a third element having an index for said third. scale.

In testimony whereof I aflix my signature in presence of two witnesses.

lVlLLlAli l L. E. KEU FF EL. Witnesses MARY H. Lnwis, HELEN V. Fi'rzrnrnrox.

Copies of this patent may be obtained for five cents each, by addressing the @mmissioner of Patents,

Washington, D. G. 

